270-300 Win Mag now feasible

[CogburnR]

My barrelled action showed up yesterday. Looks Good!

I have to massage the bolt stop and magazine for longer OAL, assemble, and load some ammo.

Of course... I have no time to do it and the weather is crappy.

Thinking of starting with RL26 or RL33 and a 165 Matrix.

 

[CogburnR]

I took a little time this morning and worked on it.

I shortened the bolt stop and ejector,removed the spacer in the mag box and worked on the rails a little in the rear of the action. It feeds the dummy round with a 3.6" oal. I will probably go in and file down the ledge that holds the mag box a bit as it sticks out a little.

I installed it in a Choate stock, then mounted an EGW 20MOA rail and a 4-20x50 Nitrex TR2 scope with Burris Signature Zee rings.

 

[dwm]

So are you guys using something like Redding 300 Win Mag full length bushing dies with 270Cal bushings and a 300 Win Mag Seater?

Or is someone making custom dies?

 

[CogburnR]

I loaded up 5 rounds for a pressure series with RL26 69-73 grains and a 165 Matrix.

I used a Innovative collet die, then ran them through a 300wm FL die with the stem removed and then necked them down in a 270WSM die with a spacer between the die and shellholder. Seated with a 300WM seater.

OAL 3.6" about .012" off the lands. Shot cleaning in between every round and sighting in at the same time. Last three went less than 1.5" in 25-35mph winds with an unsteady position 71,72, and 73g RL26. Looks like 71g of RL26 should be a good spot but my buddy has my chronograph so no speeds.

 

[Big Jake Duke]

So are you guys using something like Redding 300 Win Mag full length bushing dies with 270Cal bushings and a 300 Win Mag Seater?

Or is someone making custom dies?

Redding has the dies. They arent on their website, but if you call them , i think Aaron is the guy with the info.

Originally i used a 300 win mag body die and a 270weatherby mag for necking and seating. I just had them adjusted extremely long. The redding package is far simpler.

 

[Big Jake Duke]

I took a little time this morning and worked on it.

I shortened the bolt stop and ejector,removed the spacer in the mag box and worked on the rails a little in the rear of the action. It feeds the dummy round with a 3.6" oal. I will probably go in and file down the ledge that holds the mag box a bit as it sticks out a little.

I installed it in a Choate stock, then mounted an EGW 20MOA rail and a 4-20x50 Nitrex TR2 scope with Burris Signature Zee rings.

Very nice- i have the other style Choate on my 25-06AI. HOW DO YOU LIKE THE TACTICAL MODEL?

 

[CogburnR]

The choate works well on the ground prone. It is out of its element on the bench. The slanted forearm and flat bottomed buttstock are the downfalls of the design. I bought this stock long before they came out with the varmint version (which would work better for my use). Also, Harris bipods rock when mounted to it. It makes it a little more challenging to shoot off the bench. There are not a lot of cheaper stocks offered for a la m70...choate doesn't offer the varmint stock, boyds doesn't offer thumbholes with a heavy barrel channel, etc. The factory Laredo stock has some issues but I might try to get it back from the guy I sold it to. I also have a pretty decent Fajen walnut stock for his thing that I use sometimes when hunting.

Just a plain m40 type or m24 stock would be better I think.

I loaded up some Rl33 with the 165 Matrix, 72-76g. Just necking my fired brass didn't produce decent results so they got the full treatment again. Pushed the shoulders back 1-2 thou, ran them through the Innovative collet die and necked them. I ordered a bunch of de-mil'ed federal brass to try, it was on sale 84$ for 200 shipped.

I will have to get my chronograph pryed away from my buddy(we bought it together a long time ago), he has a slow 270 he is trying to get speed out of. A magnetospeed is on my list.

 

[FEENIX]

You guys are having way too much fun!

Ed

 

[KnowledgeSeeker]

The 270 Winmag...I wonder why winchester or Remington never came out with this.
Anyway, I wonder how this cartridge will compare to the standard 270WSM.
The 270 has always been my favorite round even though the 6.5 and 7mm are better for long range, but now since the 270 is no longer being looked at as the red headed step child, bullet manufactures are starting to enable it to be just as good as the 6.5s and 7mm's for long range.

I'm sorry to be a party pooper but isn't a .270/300WM essentially a 7mmREM Mag the only essential difference I can see is a .142mm/0.0056" in diameter of the ballistic and some minor differences in the lengths due to compensating for the necking down of the same brass (according to SAAMI specs)? Or is there a key element I'm missing here? I'm not commenting to challenge but to learn!lightbulb

 

[CogburnR]

The 270-300wm is simply the 300wm necked down, not the 7RM necked down. It has about 10% more powder capacity than a WSM and probably close to that compared to the 7RM because of the increased OAL we run(3.6" or so). So, it should be capable of 5% speed gains over a 7RM which means like 3200fps with a 165g bullet that has a bc of .650 or 170g with a bc of .662 at 3150 or so.It also gets into the next slower powder class... which helps.

Look at the ballistics, it has advantages. A 7RM(I have one,as well as a 7WSM and 2-270WSM's) runs a 168 Berger VLD at 3000fps for a bullet drop of 255" at 1000 with 1668fps and 1032 Ft/lbs, The 270-300WM runs the 170Berger 3150 for 219" drop with 1859fps and 1305ft/lbs at 1000 yards. So, 36" of drop and a couple hundred ft/lbs. of energy and speed at a 1000 is nothing to sneeze at, also 5" or so less wind drift.

In my case I had a 300wm that needed a barrel, quite a bit of 300wm brass, a LOT of 270 bullets, and a LOT of powder that will work well for it. So, it was a pretty easy choice for me. I also did not want to shoot bullets much over 170g because I do not want to put a brake on it(I have a 300RUM with a brake (230's at 3000fps!)). The little I have shot it so far has not produced much recoil.

And I needed a new toy.gun)

 

[Longtooth32]

The 270-300wm is simply the 300wm necked down, not the 7RM necked down. It has about 10% more powder capacity than a WSM and probably close to that compared to the 7RM because of the increased OAL we run(3.6" or so). So, it should be capable of 5% speed gains over a 7RM which means like 3200fps with a 165g bullet that has a bc of .650 or 170g with a bc of .662 at 3150 or so.It also gets into the next slower powder class... which helps.

Look at the ballistics, it has advantages. A 7RM(I have one,as well as a 7WSM and 2-270WSM's) runs a 168 Berger VLD at 3000fps for a bullet drop of 255" at 1000 with 1668fps and 1032 Ft/lbs, The 270-300WM runs the 170Berger 3150 for 219" drop with 1859fps and 1305ft/lbs at 1000 yards. So, 36" of drop and a couple hundred ft/lbs. of energy and speed at a 1000 is nothing to sneeze at, also 5" or so less wind drift.

In my case I had a 300wm that needed a barrel, quite a bit of 300wm brass, a LOT of 270 bullets, and a LOT of powder that will work well for it. So, it was a pretty easy choice for me. I also did not want to shoot bullets much over 170g because I do not want to put a brake on it(I have a 300RUM with a brake (230's at 3000fps!)). The little I have shot it so far has not produced much recoil.

And I needed a new toy.gun)

How long is your barrel?

I have averaged over 3225+fps with the 170 Bergers with H1000, 7977, MagPro and Retumbo through my 28" Benchmark, 1-9, 270Wby…with Magnetospeed V3…

3380 fps with 150gr SSTs...

 

[CogburnR]

My barrel is 28" long...

Have not yet shot over my chronograph(my buddy has it!).

What kind of powder charges are you using...??? Data is always enlightening.

I have some RL33 loaded with 165 Matrix's, 72-76g for Wed. or so.

Next is probably Retumbo, then 7977, H1000, Magpro, then Us869, WC870, 7828, Magnum, RL50, etc.

Eventually, I will probably be doing HBN coatings(I have numerous 150g Trophy Bonded Tip 150's but they are nickel plated with a bc of .470 or so)

So far I have fired 5 rounds with RL26.

 

[Longtooth32]

My barrel is 28" long...

Have not yet shot over my chronograph(my buddy has it!).

What kind of powder charges are you using...??? Data is always enlightening.

I have some RL33 loaded with 165 Matrix's, 72-76g for Wed. or so.

Next is probably Retumbo, then 7977, H1000, Magpro, then Us869, WC870, 7828, Magnum, RL50, etc.

Eventually, I will probably be doing HBN coatings(I have numerous 150g Trophy Bonded Tip 150's but they are nickel plated with a bc of .470 or so)

So far I have fired 5 rounds with RL26.

My gun, my chamber. You know the reloading rules....

This is for the Berger 170s...

All, at least once fired, and only necked sized brass...with Wolf Mag primers...electronically measured, RCBS Chargemaster...Giraud trimmed after first fireform...270 Wby...mag length of 3.36"

Best loads so far...

Retumbo 77grs...ave 3246fps...ES 15

MagPro 73grs...ave 3223fps...ES 17

H1000 74grs...ave 3233...ES 12

7977 75grs...ave 3220...ES 35

Matrix 165 load...

H1000...74 grs...3227fps...ES 21

H1000...71 grs...3100fps...ES 13...very accurate load...

I have some 7828SSC that ran well with the 165 Matrix...just need to correlate it with the Magnetospeed V3...

I hope this gives you some sort of a baseline and I want to get some RL-26

 

[Big Jake Duke]

I'm sorry to be a party pooper but isn't a .270/300WM essentially a 7mmREM Mag the only essential difference I can see is a .142mm/0.0056" in diameter of the ballistic and some minor differences in the lengths due to compensating for the necking down of the same brass (according to SAAMI specs)? Or is there a key element I'm missing here? I'm not commenting to challenge but to learn!lightbulb

Thanks for the question, this round is off of the 300 win mag, not the 338 winmag. This allows for a huge gain in powder availability over a 7rem mag. I Think a 7 mag will run about 65 grains of powder and we are running a full 10 grains over that depending upon the powder. The new bullets in 270 are FINALLY better in bc than their equal weight counter parts in 7mm. You need a 1-8 twist for the top performance in this rifle for the higher bc bullets.

I have chronoed the 140 Cutting Edge Bullets at 3500fps
The nosler long range accubonds at 3400
The matrix 165s at almost 3300 and the 175s at 3200

I am still working on the berger 170 with a bc of 704. I hope. To have an accurate load at 3250 soon.

That is why this is a fun and practical project. The recoil is less than my original 300 win mag.

It is also a practical point in powder consumption. Necking a 7stw to 277 will give you more powder, but we may soon reach the point of diminishing returns.